Immunohistochemistry (IHC) for MYH3, IRF6, and GREM1 proteins and chromogenic in situ hybridization (CISH) for <i>IRF6</i> and <i>GREM1</i> genes were used to analyze postnatal unilateral right cleft lip tissue (ten patients) and control tissue (six patients). Here, IRF6 is linked to medical procedure.